Finance minister Pranab Mukherjee met prime minister Manmohan Singh here late tonight and is understood to have briefed him about his talks with West Bengal chief minister Mamata Banerjee.

Mukherjee's meeting with Singh came within hours of Trinamool MPs meeting with the prime minister to convey their serious concern over the petrol price hike issue.

Mamata, who has been pushing for a special financial package from the Centre to help West Bengal tide over acute cash crunch, had an over hour-long meeting with Mukherjee earlier in the day in Kolkata after which she expressed disappointment about its outcome.

"Nothing substantial came out. This type of meetings were also held in the past," Banerjee told Bengali news channel 'Star Ananda' after the meeting with Mukherjee.

Wondering how she could manage the state's economy left behind by the previous Left Front government, the chief minister said "we have to spend crores and crores of rupees for meeting salaries, allowances and other requirements. Where is the central assistance?"

She also gave an ultimatum to the UPA government saying her party would not remain in the coalition if it effects another hike in prices of petro products.

"Trinamool Congress will not remain in the UPA government if the Centre resorts to another increase in prices of diesel, kerosene and LPG," Banerjee said.