The phrase "increase his role" is correct and usable in written English.
It can be used when discussing the expansion or enhancement of someone's responsibilities or position within a context, such as a workplace or project.
Example: "The manager decided to increase his role in the project to leverage his expertise."
Alternatives: "expand his responsibilities" or "enhance his position."
As his illness limited his ability to provide bedside care, he increased his role as an academic and professional mentor.
Most important to Carlson was winning a Stanley Cup, but individual accomplishments were discussed, too, from increasing his role on the ice to making an All-Star Game.
With my father increasing his role in the FAA Federal Aviation Administrationn), we moved several times.
In the latter part of the season, Smith increased his role and was elevated over Isaiah Williams as the number-two receiver across from Darrius Heyward-Bey.
Jordanian analysts said the trip seemed to be part of the king's efforts to increase his regional role as well as a message to the Palestinians that they could not avoid negotiations with Israel even as they sought unity between the Fatah-dominated Palestinian Authority and Hamas, which rules in Gaza.
If he plays regularly with Xerez it would increase his chances of playing a role with the United States national team, which will begin the final phase of regional qualifying for the 2010 World Cup against Mexico in Columbus, Ohio, on Feb. 11.
And when told a good start to his temporary managerial stint could increase his chances of landing the role on a permanent basis, he added: "It may well do, but that's out of my control.
Flanders's role increased his awareness of the labor and business assets in New England.
Hardy gained 30 pound for the role, increasing his weight to 198 pound.
His geographical range was also increased by his role as Lord Krishna in the Canadian-produced fable Masala, which was partly a meditation on the Air India disaster of 1985.
