HOUSTON -- With a little more than two weeks remaining before the deadline to sign Draft picks, the Astros agreed to a deal with right-hander Ross Seaton, their third-round supplemental pick from this year's First-Year Player Draft.

Seaton received a signing bonus of $700,000, believed to be the highest of any player selected 109th in the Draft and twice what other players drafted around him received.

The Astros also plan to cover his college expenses should Seaton, who recently graduated from Second Baptist High School in Houston, decide to pursue a degree.

Seaton will receive an extra $1,000 when he is promoted to Double-A Corpus Christi and stays there for at least 90 days. He'll get an additional $1,500 when he is promoted to Triple-A Round Rock and stays for 90 days and another $5,000 when he joins the Astros and stays for 90 days.

"We tried to recognize that there are parameters within the slotting process and discuss our willingness to try to be flexible within our system," general manager Ed Wade said. "[Owner Drayton McLane] expressed a willingness to be flexible on a number of occasions. In analyzing the talent, we thought there would be maybe two or three instances where it would make sense to push the envelope a little bit. We've been fortunate to be 2-for-2 so far."

Seaton, 18, will join the Astros Rookie League affiliate in Greeneville on Saturday.

"I wanted to be an Astro the whole time," he said. "To play for the hometown team was obviously a goal as a professional ballplayer. We negotiated and ended up coming to terms, so it all worked out fine."

During his senior season this year, Seaton posted an 8-2 record with a 1.32 ERA and 120 strikeouts over 74 innings pitched, earning All-Area Code and Texas Area Scouts Association All-Star honors.

A member of TAPPS 4-5A first-team during the past three seasons and a two-time first-team all-state honoree, Seaton was ranked 28th on Baseball America's 2008 June Draft rankings.

"Ross is a unique addition, outside of his baseball ability and his pitching ability," Astros director of amatuer scouting Bobby Heck said. "He would be a prospect as a position player as well, but did take off on the mound this year. Obviously, we think very highly of him.

"His academic acumen is such that not only was he courted highly at Tulane, but also Stanford, Rice and Vanderbilt, just to name some of the schools. He graduated No. 1 in his class as well as this year's valedictorian, and also the foundation that Ross' parents have put into place here made this a wise investment as an organization and made it much easier to do."

The organization views Seaton as a future big league starting pitcher.

"He has three pitches that all have downward action [fastball, changeup and curve] which is very appealing, as well of two of those pitches at times flashing above Major League average," Heck said. "We also see him as a quality strike-thrower. That being said, we see him as a rotation-type pitcher."

Seaton was one of 13 right-handed pitchers selected by the Astros in the 2008 First-Year Player Draft. The Astros have now agreed to terms with 31 total players among the 52 selected in the two-day Draft, including 14 of the first 15.

The deadline to sign Draft picks is Aug. 15.