Exhibit 99.4 CONSENT OF PERSON ABOUT TO BECOME A DIRECTOR The undersigned, Robert C. Williams, hereby consents to the reference to him in the Proxy Statement/Prospectus forming a part of the Registration Statement on Form S-4 of First Commonwealth Financial Corporation as a person who will become a director of First Commonwealth Financial Corporation upon consummation of the United National Bancorporation merger described in the Proxy Statement/Prospectus. /s/Robert C. Williams ------------------------------- Robert C. Williams June 17, 1994