Pietersen, who missed England's recent 4-0 one-day series win over Australia following his enforced retirement from limited overs internationals after England refused his wish to quit 50-over clashes while still playing Twenty20s, was in sublime form at Guildford, south-west of London.
His 234 not out featured eight sixes and 30 fours as Surrey finished the third day of four on 430 for five in reply to Lancashire's 485 for seven.
The 32-year-old reached his first hundred in 93 balls, the fastest in English domestic first-class cricket this season, by pulling Simon Kerrigan's left-arm spin for six.
After the day's play Pietersen, asked whether negotiations into his England return in 'white ball' cricket were stil ongoing, told the ESPNCricinfo website: "I think so.
"I've said before that, if the schedule was right, if they could sort my schedule out, I would love to play for another three or four years in all forms of cricket. But the schedule at the moment is a nightmare."
Elsewhere, England Test captain Andrew Strauss was in the runs as well ahead of the first of a three-Test series at The Oval, Surrey's headquarters, with 127 for Middlesex against First Division leaders Nottinghamshire at Uxbridge.